Reversible rolling under controlled tension



. y 1933- E. B. HUDSON 2,118,560

REVERSIBLE ROLLING UNDER CONTROLLED TENSION Original Filed Oct. 25, 1954 5 Sheets-Sheet l INVENTOR EDWIN 5. Huasoxv.

dbauv ATTORNEYS.

May 24, 1938. 4 E. B. HUDSON 2,118,560

REVERSIBLE ROLLING UNDER CONTROLLED TENSION Original Filed 00 23, 1934 5 Sheets-Sheet 2 Pic-1. 4.

INVENTOR Euwnv B. Hausa/v.

ATTORNEYS.

May 24, 1938. E. B. HUDSON 2,118,560

HIIIIIIIIIH *T REVERSIBLE ROLLING UNDER CONTROLLED TENSION I Original Filed Oct. 23, 1934 5 Sheets-Sheet I5 v INVENTOR fiDM/IWJ "H. /T/UD6 ON.

ATTORNEY-S May 24, 1938. E. B. HUDSON M lfifiiw REVERSIBLE ROLLING UNDER CONTROLLED TENSION Original Filed Oct. 23, 1934 5 Sheets-Sheet 4 INVENTOR' Eaw/N B. Human/v.

ATTORNEYS.

May 24, 1938.

Original Filed Oct. 25, 1954 5 Sheets-Sheet 5 INVENTOR Emma/v .5. Hausa/v.

ATTORNEYS.

Patented May 24, 1938 REVERSIBLE ROLLING UNDER coN- momnn TENSION Edwin B. Hudson, Middletown, Ohio, assignor to The American Rolling Mill Company, Middletown, Ohio, a. corporation of Ohio Original application October 23, 1934, Serial No. 749,592. Divided and this application July 15, 1935, Serial No. 31,346

2 Claims. (Cl. 80-32) My invention is addressed to the rolling of metal under tension, and will find its greatest utility in the rolling of long strips of metal back- Wardly and forwardly in a reversible mill or mill piece being rolled, and from other rolling conditions. An attempt to control the speeds of the various dynamic instrumentalities in the system in accordance with tension variations in the strip,

5 combination. For the purpose of disclosing my does not wholly succeed because, once there has 5 invention in a clear and readily appreciable manbeen a variation in the tension a variation in nenlshall describe it inaparticular embodiment, the rolled piece has been produced. Moreover it being understood that this embodiment is exit is not desired to P any great q i y of emplary only, and that my invention is not apparatus between the mill and the coiler's belimited otherwise than as set forth in the apcause this increases the length of unrollable strip 1 pended claims. A method of tension rolling between the mill and the ultimate attachment whereby end wastage is eliminated, which is deof the strip to the coiler drums. Since some of scribed and claimed in a copending application, the variations may be cumulative, control of the Ser. No. 724,931, filed May 10, 1934, and entitled speeds of the several dynamic instrumentalities is Apparatus and process for tensionedcold rolling desirable; but eca I10 p e Control s rapid 15 in reversible mills, may be employed if desired enough response to take care of the sporadic tenwith the apparatus and method of thi inv nsion variations, it is necessary to provide some tion, with such appropriate apparatus additions Thea-11S Which Will p the tension st a d as will be understood from a reading of the said va y in p te of the a to s tending to p copending case. duce tension change, and then to control speeds 20 This is a division of my (go-pending applicain accordance with variations of elongation. tion ser. No. 749,592, filed October 23, 1934, and s mpli s ns t ta up at ast a rt entitled Reversible roiling under controlled tenleng of St p under a COIIStaht fOrCey, sion. there is ordinarily desired in tension rolling a It has hitherto been suggested to roll metal of pos t v t s on di a a greater tension 25 strip length and sheet width backwardly and the Strip on the outgoin e Of e ll than forwardly through a mill, say, of the four-hi'gh on e in min i e- Since he mill is a retype with small working 011 capable of making a versible mill, this condition must likewise be made heavy reduction per pass. On either side of the reversiblemill an apparatus in the nature of a tight coiler The s lu f th s Problems constitutes h so is placed. The coiler ahead of the mill, when the major je t of my v o to with t e strip is moving in one direction, is driven to exert provision of a relatively Simple and compact pthe desired forward tension on the piece, while Paratus s y p in p The ary the coiler behind the mill is braked to exert the ts of my vent w l be und st od y desired back tension. one skilled in the art upon reading these specifica- 35 Each coiler is arranged to act alternately as a $10115, wherein I Shall describe the aforesaid braking or pulling device as the direction of rollexemplary embodiment- Reference is now made ing is changed. to the drawings wherein:

It will be clear that a system of this kind pre- 1 is a Vertical Sectional View of y D- sents certain problems, some of which will be pa atus w h p s removed f r the sak of clearset forth. In the coiling devices, whether used 11658- as pullers or as brakes, for a given force applied 2 is an elevational View Bin adjustable to the shafts of the drums, the force applied to aocumulator devicethe strip will vary inversely to the diameter of 3 is a P View Of the mill. One f the the coils on the drums, as will be obvious. The ooilers, and the drives thereformost perfect rolling under tension is dependent Fig. 4 is an end elevation thereof. upon continuously uniform and unvarying t Fig. 5 is a side elevation of a coiler and its sion, since with a given setting of the rolls a difmountings ference in gauge will follow a difference in ten- F 6 is an e elevation thereofsion. Even if provision were made in some way Fig. 7 is a plan view of my ac umul tion 50 that the pulling and braking coilers could exert F 8 s a d elevation he e f.

a constant force upon the strip, yet one would Fig. 9 is an elevational view of an exempl be confronted with those continual and sporadic braking apparatus variations in elongation which arise from non- Briefly, in the practice of my invention I prouniformity of gauge, strain or hardness in the Vide a reversible mill l (reference is made to Figs. 1 and 2 for a better understanding of this brief description). This mill is preferably of the four-high type. Guide rolls 2 and 2a are shown adjacent the mill. On either side of the mill there is a coiler, the drums of which are indicated at 3 and 4. These drums, instead of being mounted in the ordinary frames, are held in crook-shaped cradles 4a and 5 which are pivoted to the coiler frames 6 and I below the drums as at 8 and 9. Thus, as the cradles tilt, the drums are brought closer to or further from the rolls of the mill. Hydraulic or other fluid pressure cylinders I0 and I I tend to rock the cradles so as to urge the drums away from the mill rolls under constant forces. In this way I have provided for a structure in which sporadic variations in elongation may occur without affecting tension, since these variations are taken up by movements of the cradles and drums. The extent of movement of the drums is, of course, limited; so that it is advisable to control the speeds of the various instrumentalities in accordance with variations in elongation. Each drum will be understood to have a drive, such as an electric motor. Rheostats for these motors respectively are shown at I2 and I3, each equipped with sheaves I4 and I5. Cables I6 and I1, connected with arms on the respective cradles, pass over these sheaves and are counterweighted as at I8 and I9. Thus variations in the positions of the cradles will produce corresponding variations in the drum drives, although a lost motion connection may be made therebetween so that there will be a central zone of no control. It will be understood that the drums may likewise be equipped with braking means for use in lieu of a drive when any particular drum is paying out strip.

The mill may be of any suitable type, equipped or not with means for compensating for the offsetting or shifting of the position of the working rolls as the direction of rolling changes. I have shown at 20 a loading device for the entrance cradle, and at 2| a receivin device for the exit cradle. The exit cradle is tiltable so that the drum 4 will run out onto the receiving device. Overhead handling equipment is indicated at 22 and 23.

{It has been pointed out hereinabove that in most instances a positive differential in tension is desired in the direction of rolling. If this were not so, the cylinders I0 and II might continuously have equal fluid pressures imposed upon them, and might conveniently be loaded from the same accumulator. But if rolling is proceeding with movement of the strip 24 to the right in Fig. 1, there will preferably be greater fluid pressure in the cylinder I I than in the cylinder I0; and when the mill is reversed the reverse of these conditions is desired. This may be accomplished by providing a separate accumulator for each of the cylinders, and effectively changing the weights on the accumulators as required. I have devised a simple apparatus for this purpose which I have shown in Fig. 2. Here the accumulator comprises a cylinder 25 mounted on trunnions 25 in a frame 21. A piston, is pivoted to a connecting rod indicated at 28, pivoted in turn to a yoke 29. Rods 30 and 3i are connected at one end to this yoke, pass externally of the cylinder and are guided thereon by rolls 32. Weights 33 are connected to these rods. Connection to the cylinder may be made through a trunnion, and I have indicated at 34 a line connecting the cylinder 25 with a cylinder II on one of the cradles. I branch 35 of the line may lead to a pump for oil, water, or whatever pressure fluid is desired. A gauge 36 may be calibrated to read in pressure or in strip tension. It will be understood that the fluid pressure produced by this type of accumulator may be readily varied by tilting the cylinder 25 on its trunnions. The pressure will be greatest with the cylinder in a vertical position, and will be scaled down to zero as the cylinder is turned in either direction through an angle of 90 degrees. Accumulators of this type form a facile means of adjusting the forces acting on the take up means, speedily and accurate- 1y. The cylinders may be tilted by machinery, and the tilting of them, may, by simple and readily understandable means, be made automatically responsive to a reversal of the mill.

I shall now proceed to a more particular description of an exemplary embodiment of the various mechanisms which I employ. I have shown in Figs. 3 and 4 the mill, one of the coilers, and the drives therefor. A motor 3i, for driving the mill, is reversible or is equipped with a reversible drive. It is directly connected, driving through a suitable coupling 39, a mill pinion stand of known type. Splined shafts 4i connect the pinions of the stand with the rolls Ia of the mill.

A second motor 42 drives a gear box 44. The low speed shaft of this gear box is connected through a universal coupling 46 and a splined shaft 41 directly to the drum 3 of one of the coilers. The high speed shaft of the pinion stand is connected by a coupling 45 to the shaft 48 of a braking device. This shaft bears a drum 4!! connected thereto by an over running clutch located within the drum. The over-running clutch makes it unnecessary otherwise to connect and disconnect the brake. Cables 50 are wound around the drum to react frictionally therewith. The braking arrangement is more clearly shown in Fig. 9, where 49 again indicates the drum, and 50 the cable or cables. The cables are dead-ended to a base as at 50a. The base bears a standard 5Ia, to which a scale beam 5| is pivoted as at 5Ib. The cables 50 are connected with the scale beam 5| as at 50!). Instead of two separate cables a single cable may be used, which cable is looped over the means 501), which means may take theform of a sheave. A reversible motor 52 is mounted upon the scale beam, and bears a v threaded shaft 52a extending therealong. A

weight 5Ic is threaded on the shaft 52a, and is arranged to move along the scale beam when driven by the motor 52. It will be clear that as the weight 5Ic (which has provision for being additionally loaded as desired) is moved outwardly along the scale beam, the tension on the cables 50 will be increased, and the braking action, and therefore the back tension on the piece being rolled, will likewise be increased.

The motor 52 may be controlled by hand if desired, but it is more convenient to do this automatically to control the braking action in such a way that the back tension may be maintained uniform. Since at the time of rolling in the one direction that coiler which is braked will not be positively driven by its corresponding driven motor, such a control amounts to a control of a dynamic instrumentality in the assembly, and may be effected by similar means. It is convenient to attach a switch to the corresponding cradle, say, cradle 4 in Fig. 1, so that when this cradle has rocked a predetermined distance in a counterclockwise direction the motor 52 will be started up and driven forwardly so as to move the weight aiiaaco Eiic outwardly along the scale B until the said motion of the cradle has been arrested. Like wise when the cradle moves a predetermined distance in a clockwise direction, a switch actuated thereby is effective to start the motor 52 in a reverse direction so as to bring the weight tie inwardly along the scale beam until the motion of the cradle has stopped. With the suggestion of the automatic operation of the motor 52, the switching arrangement will be blear to one skilled in the art.

The over-running clutch referred to, located within the drum it or in connection with the shaft M, renders the brake ineffective when the corresponding coiler drum is being positively driven in a pulling direction by its motor. However, during the threading operations of the apparatus, it may sometimes be necessary to drive the coiler motor in a reverse direction, which indicates the advisability of the provision of some means to relieve the braking action. To this end I provide an ordinary thruster 52?), located under an end of the scale beam M. This thruster may be of an ordinary type well known in the art, and special description thereof is not required. Its function is to push the free end of the scale beam upwardly, thereby relieving tension on the cables at, and it may be, and preferably is, actuated by a hand control, since relief of the braking action will be required only during threading operations.

The cradle 4a is shown as comprising side pieces 4b and transverse members 53 and 54. The cylinder l0. has a plunger assembly Mia, terminating in a yoke lllb. This yoke is connected by rods We to the cross piece 53. Below the cylinder assembly a stop means 55 may be provided, which may be resilient or not as desired.

Further details of the coiling devices are shown in Figs. 5 and 6, wherein it will be seen that the drum 3 has bearing members 56 and 511, which are in the form of sheaves or rollers permitting motion of the drum along the cradle members tb when it is desired to remove the drum for loading or rewindlng purposes. Suitable anti-friction bearing means are located between the sheave members and the shafts of the drum. The splined shaft 41 from the drive is connected to the drum shaft by a slidable connecting member 58. To connect and disconnect the drum from the shaft 41, I provide a power means to operate the slidable connecting member. This comprises a pressure cylinder 59, arms 60 connected to the piston thereof and also to the connecting member 58. The arms are finally connected to the frame of the coiler by a linkage 6| forming a moving fulcrum therefor. Latch means BZ may be provided to prevent accidental dislodgment of the drum from the crock of the coiler.

An exemplary form of my variable accumulator is shown in Figs. '7 and 8. 63 represents the frame of the apparatus. The cylinder is again shown at 25 and the trunnions at 26. Segmental gear wheels M on the trunnions mesh with pinions 65 on a shaft 66 journaledin frame extensions 63a. The shaft bears a gear 61 which is connected by a change speed gearing arrangement indicated generally at 68 to a motor 69.

The yoke is again indicated at 29 and the external rods at 30 and 3|. In this particular embodiment, ears l0 and H on the cylinder 25 bear wheels it which serve as guides for the rods. The weights at are attached to the ends of the rods which are connected by a yoke it. Spring cushioning means it are shown in the upper yoke.

In order togive to the roller in a place readily accessible to him a definite indication of forward and back tensional have shown indicators b and b on the frame of the mill ll. These indicators are driven from the respective hydraulic accumulators in any way desired. Preferably they are calibrated to show tension in convenient units. Actually they indicate the angularity of the hydraulic accumulators, and may be directly driven from the trunnions it of the accumulators through flexible shafts. I find it more convenient, however, to connect a selsyn motor, indicated at C in Figs. 7 and 8, with the corresponding one of the-indicators b or b in Figure l, which is equipped with a selsyn motor. The connections therefore become electric rather than mechanical, and the indicators give a definite indication of the position of the accumulators. They may then be calibrated in the desired tension units.

It will be clear that my invention is not restricted to the particular embodiments of apparatus which I have described in some detail. My invention as claimed may be practiced with other apparatus; and modifications in my invention may be made without departing from the spirit thereof.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent, is:-

1. In combination a reversible mill for rolling strip metal, means for exerting a pulling force on said strip metal, means for rendering the tension on said strip metal independent of variations in elongation, said last mentioned means comprising means for taking up said strip metal under apredetermined force which in terms of tension on the strip is constant. during the operation of the mill in any one direction, said force being exerted by fluid pressure means, including a pressure cylinder, a fluid pressure accumulator connected to said cylinder, said accumulator being tiltable to control the pressure exerted on the fluid therein, and means for tilting said accumulater when said mill is reversed so as to change the value of said constant tension upon reversal of the mill.

2. In combination a reversible mill for rolling a strip material, means on one side of said mill for exerting a tensional force on said material and intermediate said mill and said last mentioned means, means for rendering the tension on said strip independent of elongation variations produced by said mill, said last mentioned means comprising means for taking up said strip under a force which is constant during the operation of said mill in any one direction, said means comprising a fluid pressure cylinder, a tiltable accumulator connected thereto and means for tilting said accumulator, and means for automatically changing the force exerted by said take-up means when the direction of rolling of said mill is changed, said means comprising means for varying the tilting of said accumulator when said direction of rolling is changed.

EDWIN B. HUDSON. 

